sq/README.md
Neil O'Toole c810d17eec
#229: sq diff ready for beta release (#239)
* sq config edit: fixed glaring bug that prevented editing a source

* Refine sq diff
2023-05-25 21:58:43 -06:00

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sq data wrangler

sq is a command line tool that provides jq-style access to structured data sources: SQL databases, or document formats like CSV or Excel.

sq

sq executes jq-like queries, or database-native SQL. It can perform cross-source joins.

sq outputs to a multitude of formats including JSON, Excel, CSV, HTML, Markdown and XML, and can insert query results directly to a SQL database. sq can also inspect sources to view metadata about the source structure (tables, columns, size) and has commands for common database operations to copy, truncate, and drop tables.

Find out more at sq.io.

Install

macOS

brew install neilotoole/sq/sq

Linux

/bin/sh -c "$(curl -fsSL https://sq.io/install.sh)"

Windows

scoop bucket add sq https://github.com/neilotoole/sq
scoop install sq

Go

go install github.com/neilotoole/sq

See other install options.

Overview

Use sq help to see command help. Docs are over at sq.io. Read the overview, and tutorial. The cookbook has recipes for common tasks, and the query guide covers sq's query language.

The major concept is: sq operates on data sources, which are treated as SQL databases (even if the source is really a CSV or XLSX file etc.).

In a nutshell, you sq add a source (giving it a handle), and then execute commands against the source.

Sources

Initially there are no sources.

$ sq ls

Let's add a source. First we'll add a SQLite database, but this could also be Postgres, SQL Server, Excel, etc. Download the sample DB, and sq add the source.

$ wget https://sq.io/testdata/sakila.db

$ sq add ./sakila.db
@sakila  sqlite3  sakila.db

$ sq ls -v
HANDLE   ACTIVE  DRIVER   LOCATION                         OPTIONS
@sakila  active  sqlite3  sqlite3:///Users/demo/sakila.db

$ sq ping @sakila
@sakila       1ms  pong

$ sq src
@sakila  sqlite3  sakila.db

The sq ping command simply pings the source to verify that it's available.

sq src lists the active source, which in our case is @sakila. You can change the active source using sq src @other_src. When there's an active source specified, you can usually omit the handle from sq commands. Thus you could instead do:

$ sq ping
@sakila  1ms  pong

Query

Fundamentally, sq is for querying data. The jq-style syntax is covered in detail in the query guide.

$ sq '.actor | .actor_id < 100 | .[0:3]'
actor_id  first_name  last_name     last_update
1         PENELOPE    GUINESS       2020-02-15T06:59:28Z
2         NICK        WAHLBERG      2020-02-15T06:59:28Z
3         ED          CHASE         2020-02-15T06:59:28Z

The above query selected some rows from the actor table. You could also use native SQL, e.g.:

$ sq sql 'SELECT * FROM actor WHERE actor_id < 100 LIMIT 3'
actor_id  first_name  last_name  last_update
1         PENELOPE    GUINESS    2020-02-15T06:59:28Z
2         NICK        WAHLBERG   2020-02-15T06:59:28Z
3         ED          CHASE      2020-02-15T06:59:28Z

But we're flying a bit blind here: how did we know about the actor table?

Inspect

sq inspect is your friend (output abbreviated):

$ sq inspect
HANDLE   DRIVER   NAME       FQ NAME         SIZE   TABLES  LOCATION
@sakila  sqlite3  sakila.db  sakila.db/main  5.6MB  21      sqlite3:///Users/demo/sakila.db

TABLE                   ROWS   COL NAMES
actor                   200    actor_id, first_name, last_name, last_update
address                 603    address_id, address, address2, district, city_id, postal_code, phone, last_update
category                16     category_id, name, last_update

Use sq inspect -v to see more detail. Or use -j to get JSON output:

sq inspect -j

Combine sq inspect with jq for some useful capabilities. Here's how to list all the table names in the active source:

$ sq inspect -j | jq -r '.tables[] | .name'
actor
address
category
city
country
customer
[...]

And here's how you could export each table to a CSV file:

$ sq inspect -j | jq -r '.tables[] | .name' | xargs -I % sq .% --csv --output %.csv
$ ls
actor.csv     city.csv	    customer_list.csv  film_category.csv  inventory.csv  rental.csv		     staff.csv
address.csv   country.csv   film.csv	       film_list.csv	  language.csv	 sales_by_film_category.csv  staff_list.csv
category.csv  customer.csv  film_actor.csv     film_text.csv	  payment.csv	 sales_by_store.csv	     store.csv

Note that you can also inspect an individual table:

$ sq inspect @sakila.actor
TABLE  ROWS  TYPE   SIZE  NUM COLS  COL NAMES
actor  200   table  -     4         actor_id, first_name, last_name, last_update

Diff

Use sq diff to compare source metadata, or row data.

sq diff

Insert query results

sq query results can be output in various formats (JSON, XML, CSV, etc), and can also be "outputted" as an insert into database sources.

That is, you can use sq to insert results from a Postgres query into a MySQL table, or copy an Excel worksheet into a SQLite table, or a push a CSV file into a SQL Server table etc.

Note: If you want to copy a table inside the same (database) source, use sq tbl copy instead, which uses the database's native table copy functionality.

For this example, we'll insert an Excel worksheet into our @sakila SQLite database. First, we download the XLSX file, and sq add it as a source.

$ wget https://sq.io/testdata/xl_demo.xlsx

$ sq add ./xl_demo.xlsx --ingest.header=true
@xl_demo  xlsx  xl_demo.xlsx

$ sq @xl_demo.person
uid  username    email                  address_id
1    neilotoole  neilotoole@apache.org  1
2    ksoze       kaiser@soze.org        2
3    kubla       kubla@khan.mn          NULL
[...]

Now, execute the same query, but this time sq inserts the results into a new table (person) in the SQLite @sakila source:

$ sq @xl_demo.person --insert @sakila.person
Inserted 7 rows into @sakila.person

$ sq inspect @sakila.person
TABLE   ROWS  COL NAMES
person  7     uid, username, email, address_id

$ sq @sakila.person
uid  username    email                  address_id
1    neilotoole  neilotoole@apache.org  1
2    ksoze       kaiser@soze.org        2
3    kubla       kubla@khan.mn          NULL
[...]

Cross-source join

sq has rudimentary support for cross-source joins. That is, you can join an Excel worksheet with a CSV file, or Postgres table, etc.

See the tutorial for further details, but given an Excel source @xl_demo and a CSV source @csv_demo, you can do:

$ sq '@csv_demo.data, @xl_demo.address | join(.D == .address_id) | .C, .city'
C                      city
neilotoole@apache.org  Washington
kaiser@soze.org        Ulan Bator
nikola@tesla.rs        Washington
augustus@caesar.org    Ulan Bator
plato@athens.gr        Washington

Table commands

sq provides several handy commands for working with tables: tbl copy, tbl truncate and tbl drop. Note that these commands work directly against SQL database sources, using their native SQL commands.

$ sq tbl copy .actor .actor_copy
Copied table: @sakila.actor --> @sakila.actor_copy (200 rows copied)

$ sq tbl truncate .actor_copy
Truncated 200 rows from @sakila.actor_copy

$ sq tbl drop .actor_copy
Dropped table @sakila.actor_copy

UNIX pipes

For file-based sources (such as CSV or XLSX), you can sq add the source file, but you can also pipe it:

$ cat ./example.xlsx | sq .Sheet1

Similarly, you can inspect:

$ cat ./example.xlsx | sq inspect

Drivers

sq knows how to deal with a data source type via a driver implementation. To view the installed/supported drivers:

$ sq driver ls
DRIVER     DESCRIPTION                          
sqlite3    SQLite                               
postgres   PostgreSQL                           
sqlserver  Microsoft SQL Server / Azure SQL Edge
mysql      MySQL                                
csv        Comma-Separated Values               
tsv        Tab-Separated Values                 
json       JSON                                 
jsona      JSON Array: LF-delimited JSON arrays 
jsonl      JSON Lines: LF-delimited JSON objects
xlsx       Microsoft Excel XLSX                 

Output formats

sq has many output formats:

CHANGELOG

See CHANGELOG.md.

Acknowledgements